Don’t dismiss Lamarck
Your January 31 special birthday edition on Darwin (SN: 1/31/09, p. 17) was excellent, but I believe that science has allowed Jean-Baptiste Lamarck’s contributions to be overshadowed by Darwin’s. The change that can occur to an organism’s genetic makeup during its own lifetime harks away from Darwin’s slow evolutionary process by chance mutations and argues toward Lamarck’s heritable changes within a lifetime.
Robert Powell, Austin, Texas
Take a vote of biologists today and Darwin will win hands down. But I predict that in 20 years that will change, and the new most influential biologist will be Lamarck. The turning point was the Human Genome Project. It is now becoming clear that a type of formative causation may be real, in spite of the fact that most biologists still gag on the word. Just because one can show that natural selection works does not prove that it is the correct mechanism.
O. Frank Turner, Pueblo West, Colo.
Lamarck did argue that traits acquired during an organism’s lifetime could be inherited, a notion almost universally accepted in his day. Since then, the term “Lamarckian inheritance” has been applied to several mechanisms, including some far from his original ideas. Many of his ideas have been largely discredited. Yet, the late Stephen Jay Gould wrote eloquently about Lamarck, calling him a fine scientist, and Darwin himself acknowledged Lamarck’s contributions to science. Scientists today do agree that inheritance is messier than previously realized and that it involves more than genes. For example, epigenetic changes to the way DNA is tagged or packaged — triggered by environmental factors such as stress or diet — may be inherited. But the various kinds of inheritance have themselves evolved through Darwinian natural selection, which does not require that selection be based only on genetics . — Rachel Ehrenberg